1 /*
2 * Copyright (C) 2014 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/sysinfo.h>
30
31 #include <dirent.h>
32 #include <stdio.h>
33 #include <string.h>
34 #include <unistd.h>
35
36 #include "private/get_cpu_count_from_string.h"
37 #include "private/ScopedReaddir.h"
38
__matches_cpuN(const char * s)39 static bool __matches_cpuN(const char* s) {
40 // The %c trick is to ensure that we have the anchored match "^cpu[0-9]+$".
41 unsigned cpu;
42 char dummy;
43 return (sscanf(s, "cpu%u%c", &cpu, &dummy) == 1);
44 }
45
get_nprocs_conf()46 int get_nprocs_conf() {
47 // On x86 kernels you can use /proc/cpuinfo for this, but on ARM kernels offline CPUs disappear
48 // from there. This method works on both.
49 ScopedReaddir reader("/sys/devices/system/cpu");
50 if (reader.IsBad()) {
51 return 1;
52 }
53
54 int result = 0;
55 dirent* entry;
56 while ((entry = reader.ReadEntry()) != NULL) {
57 if (entry->d_type == DT_DIR && __matches_cpuN(entry->d_name)) {
58 ++result;
59 }
60 }
61 return result;
62 }
63
get_nprocs()64 int get_nprocs() {
65 int cpu_count = 1;
66 FILE* fp = fopen("/sys/devices/system/cpu/online", "re");
67 if (fp != nullptr) {
68 char* line = nullptr;
69 size_t len = 0;
70 if (getline(&line, &len, fp) != -1) {
71 cpu_count = GetCpuCountFromString(line);
72 free(line);
73 }
74 fclose(fp);
75 }
76 return cpu_count;
77 }
78
get_phys_pages()79 long get_phys_pages() {
80 struct sysinfo si;
81 sysinfo(&si);
82 return (si.totalram * si.mem_unit) / sysconf(_SC_PAGE_SIZE);
83 }
84
get_avphys_pages()85 long get_avphys_pages() {
86 struct sysinfo si;
87 sysinfo(&si);
88 return ((si.freeram + si.bufferram) * si.mem_unit) / sysconf(_SC_PAGE_SIZE);
89 }
90